The present invention relates to a microscope photometer having a diaphragm with rectangular aperture disposed in an intermediate-image plane.
In known microphotometric arrangements, measurement diaphragms are, as a rule, disposed in a plane in front of the receiver used for detection, said plane being conjugate to the specimen plane. Such diaphragms are frequently made replaceable, to permit use of different measurement diaphragms, of form adapted to particular specimen detail to be detected. For example, slit-shaped or rectangular diaphragms are used if strip-shaped or elongate details of the specimen are to be examined.
Adjusted adaptation of specimen detail of interest to the measurement diaphragm is effected by displacing the specimen in the specimen plane, either by hand or by a so-called scanning stage which can be motor-driven in two directions (X, Y) and which also permits of sequential scanning in any direction of the specimen structure to be measured.
Further, West German Pat. No. 2,729,024, discloses that scanning movement of the specimen image over the photometer diaphragm may be effected by controlled displacement of a lens member in two directions (X, Y).
In the case of rectangular diaphragms, for example slit diaphragms, it is also necessary to adjust for correlation of angular orientation of diaphragm aperture with that of specimen detail. Such rotary displacement has heretofore been effected solely via manipulation in the specimen plane, a procedure which is problematic during a scanning process and which when working with large imaging scales, requires a rotatable stage whose axis must correspond very precisely to the optical axis of the imaging system.